Apparatus for shell freezing of heat sensitive liquids



1955 s. M. BROADWIN 3,199,216

APPARATUS FOR SHELL FREEZING OF HEAT SENSITIVE LIQUIDS Filed Aug. 9.1961 INVENTOR.

5/7/7UEL IV. BRO/1D w/A United States Patent C 3 199,216 APPARATUS FURSEliELL FREEZING OF HEAT SENSTTTVE LTQUTDS Samuel M. roadwin, 301 E.62nd St., New York 21, N.Y. Filed Aug. 9, 1961, Ser. No. 130,28-3 6Claims. (Ci. 34-92} This invention comprises of a new method and a noveldevice for evaporating or shell-freezing of heat sensitive liquids, suchas organic fluids, and an inexpensive, rapid, and safe method ofstoppering the fluid container without releasing the vacuum, thuspreserving the dried sample from decay due to oxygen or water vapor inthe air.

The rotating container is not axially rotated as in conventionalcentrifugal devices, but is part of a greater radius, thereby allowingincreased centrifugal force with lessened speed. Further, this devicepermits turning in a complete circle by external means, thus allowingfor vacuum connections without the necessity of a rotating vacuum sealas in conventional devices.

The stoppering device is manually operated, and consists of a rubberstopper fastened by a pin to a shaft that is separated from theevacuated area by a rubber, or other stretchable material, diaphragm.The shaft is held outwardly against atmospheric pressure by a spring.When it is desired to stopper the flask situated below the stopper, thespring is depressed until the stopper is firmly inserted in the flask,at that point the vacuum is released. The stopper is held in position bythe weight of the air and the pin removed by releasing the spring.

The device of this invention is inherent in the method thereof andembodies means for eccentrically rotating a heat sensitive liquid in acontainer around an external center, heat producing means, vacuumretaining means, vacuum sealing means, vacuum stoppering means, vacuumreleasing means, means for adjustment of speed of rotation, means foradjustment of centrifugal thrust, and a means for disassembling thedevice for cleaning purposes.

Various further objects and advantages of this invention will beapparent from the description contained in the specification herein. Itmay be pointed out that present methods for vacuum stoppering in thelaboratory require heat-sealing of the glass container, which is bothdangerous and restrictive in the size of glassware. Further, as thisdevice eliminates the rotating vacuum seal found in conventional devicesit enables the operator to achieve vacuum pressures to .01 micron.

The invention will be further described by reference to the accompanyingdrawing which is made part of this specification. The drawing is acomposite sectional view of the evaporator and shell-freezer.

The invention will be further described by reference to the specificform thereof shown in the drawing, but it is pointed out that such formshown i for illustrative purposes only and is merely representative ofone of the forms this invention can take. The form shown is not to beconsidered a limitation upon this invention whose scope i solelydetermined by the appended claims.

A container holding a quantity of heat sensitive liquid 8 is disposed inthe holding form having rigidly aflixed at its terminal parts twospherical bearing surfaces 4 and 9. The container is so disposed that itrests on rubber gasket 7 and on rubber supports 16 and the container 3has a capping portion 6. The spherical bearings are pivotally held inholding cups and 17. Holding cup 17 is supported by locking slide 3which is surrounding upwardly extending portion 2. Spherical bearing 9is disposed in holding cup 10 which is integral with adjustable rotatinglocking fixture and radial arm 18 which is fixed to the revolving shaftof a adjustable speed motor, here diagrammatically indicated as 19.Upwardly extending portion 2 is rigidly fixed to horizontal bed 1 whichalso has afiixed to it a motor 19 thus forming a support for the entireinstrument. Capping portion 6 rests upon gasket 7. The capping portion 6is provided with a vacuum port which is angularly disposed thereto and avacuum stopcock 14 is provided for release of the vacuum. A shaft 29 isdisposed through an outwardly expanding spring and centrally through abridging structure which is integral with capping portion 6. The shaft26 passes through a flexible diaphragm such as rubber 12 which is sealedat its outer boundary to bridging portion 21 and at its inner boundaryto shaft 20. Forming part of the shaft 2% and not shown in the drawingis a short needle which penetrates rubber stopper 13 holding it in placefor disposition in container 8. A heater 22 for accelerating the dryingtime, is disposed about the container. I

The operation of this invention will now be explained.

Container 8 is partially filled with a heat sensitive solution, andplaced in holding form 5. Bearings 4 and 9 are placed in holding cups1i) and 17 and adjustment made to fixture. 18 setting the radius of thearm. This setting is determined by previous trial and error dependentupon quantity and viscosity of the liquid. Adjustment of locking slide 3sets proper tension on bearings. Rubber stopper 13 is afiixed to pointof needle which is part of shaft 20 and vacuum stopcock 14 is closed.This portion (6 and others) is placed on gasket 7. Vacuum port 15 isconnected to a vacuum pump by means of rubber hose and pumping is begun.When a sufiicient vacuum is achieved the above mentioned portion is heldfirmly to 5 by vacuum pressure. Motor 19 is started, rotating the liquidcontainer around a common axis formed by the motor shaft. The rotatingbearings, 4 and 9, do not rotate on their own axes, and therefore do notrequire, rotary vacuum seals. Further, due to the increased turningdiameter, sufficient centrifugal force is developed at low speeds toproduce a vortex, thus extending the evaporative surfaces and holdingthe liquid against the walls of the container 8, thus preventingdestructive foaming. When the evaporative process is adjudged complete,shaft 20 is depressed, forcing rubber stopper 13 into container 8,vacuum release stopcock is opened and vacuum pump to port 15 isdetached. The rubber stopper 13 is now held firmly due to air pressureon its outward top side and vacuum pressure on its inward bottom side.Shaft 2b is released from finger pressure and spring 11 thereuponthrusts it outward, removing the needle (shaft 20) from the rubberstopper 13. The sealed flask may now be removed. At any point in theprocedure outlined above, the drying time may have been accelerated byconnecting the heater 2.2 to an electrical circuit. This heater (shownon outside of holding form 5) may be inside the vacuum system.

I claim:

1. A device for shell freezing of heat sensitive liquids which includesa centrifugal device for supporting a single container, said singlecontainer having upper and lower ends supported in said device in anangular position, a motor having a vertical drive axis and driving armextending perpendicular from said drive axis and rotated by said motor,the upper end of said container supporting device pivotally mounted at apoint on the driving axis of said motor, the lower end of said containersupporting device pivotally mounted on an outer extremity of saiddriving arm to be rotated about the motor axis to produce the necessarycentrifugal force for shell freezing of the liquid in said container,said container being closed at the lower end and having an open mouth atthe upper end, a vacuum sealing cover for the mouth of said containerand an axially movable stopper mounted for reciprocation in the sealingcover and sealing the mouth of said container, a vacuum producing sourceconnected to said vacuum upright elementsupporting a fixed sphericalbearing at the upper end, of saidangu'larly disposedexternal axiallypivotal structure and said motor driving arm vprovided with a secondspherical bearing surface and in which said angularly disposed externalaxially pivotal 2 structure is provided with fixed 'ball b'earings thatare to be mounted within the oppositely disposed'spher'icalbearinglsurfaces.

i 3. In a device according to claim 1 in which said centrifugal devicefor supporting a singlecontainer i maintained on a, centralnon-rotatable internal axis at its upper end while being rotatedaboutits angularly disposed external axis.fat its lower end andprovidedwith means to connect saidvacuum producing means to saidcontainer at its upper end without rotation of said container or vacuumproducing source. t

4. In a device according-to claim ;1 in which said vacuum sealing coverfor the mouth of said container comprises a resilient manually operatedvalve for said stopper, supported and contained in-asealed relationship,over saidtcontainer to permit producing a vacuum within,

I vsaid valve for said stopper provided with a needle as the a solesupporting'element for said stopper, means to force said stopper intothe mouth of said container to seal said container under vacuum andwithdraw said resilient manually operated valve and needle from saidstopper and mean to release said vacuum above said stopper.

5. In a device according to claim 1 means to control the speed of saidmotor and in turn the centrifugal force produced within said container.

3 6. In a device according to claim 1 in which a heat producing meanssurrounds said container and is controlled to produce a definite controlof the change 0 temperature during the vacuurn build up. I ReferencesCited by the Examiner UNITED STATES PATENTS 2,304,192 12/42 Newton 34-92X 2,324,237 7/43 Reichel.

2,388,917 11/ 45 Hormel 34-92 2,862,307 12/58 Bloomer 34 92 2,878,5813/59 Turati 34-92 2,885,788 5/59 Leviton 345 2,897,600 8/59 1 Graham34-5 2,907,117 10/59 Parkinson et a1. 3492 NORMAN YUDKOFF, PrimaryExaminer.

1. A DEVICE FOR SHELL FREEZING OF HEAT SENSITIVE LIQUIDS WHICH INCLUDESA CENTRIFUGAL DEVICE FOR SUPPORTING A SINGLE CONTAINER, SAID SINGLECONTAINER HAVING UPPER AND LOWER ENDS SUPPORTED IN SAID DEVICE IN ANANGULAR POSITION, A MOTOR HAVING A VERTICAL DRIVE AXIS AND DRIVING ARMEXTENDING PERPENDICULAR FROM SAID DRIVE AXIS AND ROTATED BY SAID MOTOR,THE UPPER END OF SAID CONTAINER SUPPORTING DEVICE PIVOTALLY MOUNTED AT APOINT ON THE DRIVING AXIS OF SAID MOTOR, THE LOWER END OF SAID CONTAINERSUPPORTING DEVICE PIVOTALLY MOUNTED ON AN OUTER EXTREMITY OF SAIDDRIVING ARM TO BE ROTATED ABOUT THE MOTOR DRIVE TO PRODUCE THE NECESSARYCENTRIFUGAL FORCE FOR SHELL FREEZING OF THE LIQUID IN SAID CONTAINER,SAID CONTAINER BEING CLOSED AT THE LOWER END AND HAVING AN OPEN MOUTH ATTHE UPPER END, A VACUUM SEALING COVER FOR THE MOUTH OF SAID CONTAINERAND AN AXIALLY MOVABLE STOPPER MOUNTED FOR RECIPROCATION IN THE SEALINGCOVER AND SEALING THE MOUTH OF SAID CONTAINER, A VACUUM PRODUCING SOURCECONNECTED TO SAID VACUUM SEALING COVER, AND A VACUUM RELEASE VALVE INSAID VACUUM SEALING COVER.